Apparatus for casting ingots.



No. 894,410. PATENTED JULY 28,1908. J. O. E. TROTZ.

APPARATUS FOR CASTING INGOTS.

APPLICATION FILED JULY 23, 1904.

2 SHEETS-SHEET l.

5T '52 I 5 55 53 Mtfii 55 v L W1 messes inuen cof at 7, I O 444% MOZMA i2: IL) 1 I54 23 A- covney PATENTED JULY 28, 1908.

' J. 0. E. TROTZ.

APPARATUS FOR CASTING INGOTS.

APPLICATION FILED JULY 23, 1904.

2 SHBETSSHEET 2.

Inuenfor dohont]. E T? Wifnesses Q53 B To /mama.

I scribed in Letters JOHAN O. E. TROTZ, OF WORCESTER, MASSACHUSETTS.

APPARATUS FOR CASTING INGOTS.

Specification of Letters Patent.

Patented July 28,1908.

Application filed July 23, 1pm. Serial No. 217,788.

To all whom it may concern:

Be it knownthat'I, JOHAN O. E. TRo'rz, a citizen ofgSweden, residing atWorcester, in the county of \Vorcester and Commonwealth ofMassachusetts, have invented a new and useful Improvement in Ap aratusfor Casting Ingots, of which the fol owing is a specification,accompanied by drawings forming a part of the same, in which Figure 1representsa side elevation of an ingot mold embodying my invention. Fig.2-

a central vertical sectional view of the same. Fig. 3 is averticalcentral sectional view of my improved mold with an ingot inclosedtherein. Fig. 4 is a detached view of the perforated steam distributingplate. Fig. 5 is a bottom and detached view-of the conical tip formingthe lower end of the apparatus and showing the annular series of openings for the escape of steam, and Fig. 6 is a vertical sectional view ofthe lowerend of the ingot mold and of the tempering chamber, shown on alarger scale.

'Similar reference letters and figures refer to similar parts in thedifferent views. V My present invention relates to an apparatus forcontinuously casting an ingot in length greatly in excess of the lengthof the forming mold by which a supply of molten metal may becontinuously fed to one end of the mold and a cast ingot be graduallywithdrawn from the opposite end of the mold without interrupting thecontinuity of the ingot during the entire rocess, thereby enablingingots of indefimte length to be cast,

and it consists in certain additions and improvements to the ap aratusshown and deatent of the United States, No. 648,091, issued to me A'ril24.,

1900 and No. 705,721, issued to me uly 29,

. 1902, as hereinafter described, the novel features being pointed outin the annexed claims.

Referring to the accompanying drawings 1 denotes the ingot moldconsistmg preferably of a cylindrical tube having its interior surfacesmoothly polished: to facilitate the withdrawal of the ingot filhediameter of the-mold 1 is slightl contreeted at its up or endformingthe-inc ined inner wall 2, an at the lower end-oi the mold 1 itsdiameter is slightly increased forming aflaring delivery opening'3' atthejlower end of the. pipe. Surrounding the mold 1 is an outer, casingpreferabl consisting of; the two sections of pipe 4 an 5, the opposingends of the sections 4 and 5 "being united by a coupling ring 6inclosing an annular space to receive a packing 7, which is com ressedby a gland 8 to allow for the longitu inal expansion and contraction ofthe inclosin pipes 4 and 5. The outer casing is provi ed at its upperend with a hollow head 9 i'nclosing an annular water space '10communicating with the annular c amber 11 between the mold 1 and theouter casing. The head 9 is provided with awater pipe 12 communicatingwith the annular chamber 10. The lower end of the casing is similarlyprovided with a hollow head 13 inclosing an annular water space 14 whichis provided with a water pipe 15, and the annular water space 14communicates with the annular chamber 11 around the mold.

A circulation of water, or other cooling medium, is maintained aroundthe ingot mold 1 for the purpose of uniformly cooling the molten metalon all sides by connecting either the pipe 12 or 15 with a suitablesource of water supply, and allowing the remaining pipe to serve as adischar e pipe. Suitably sup orted by a framewor not shown, at a slig tdistance above the upper end of the ingot mold 1 is a funnel sha edhopper 16 provided with a restricted tu ular opening 17 in its bottom,whose diameter is less than the diameter of the upper end 18 of theingot mold. The tubular opening 17 of the hopper is elevated a slightdistance above the opening 18 of the i 0t mold to allow a iree space forthe escape? ases from the molten metal in the ingot mold. At thebeginning of the casting o eration the lower end of the ingot Supportedupon the bottom 19 wit its u per edge bearing against the inner surface0 the ingot mold'is a wall'o'r dam 20 formed of some "plastic reir'actomaterial, such as fire clay or lplumbago, an thereby entirely closingthe ower end of the ingot mold 1, so that the molten metal oured throughend 18 will gradua y fill the mol The bottom 19 is carried by a head 21,provided with the openi the bottom 19 and adapted to be mclosedmold isfilled. The head 21 is detacha connected to an ingot withdrawing rod 23,

[within the mass of molten metal as the ingpt' V preferably connected atits lower end to the piston rod;- of an hydraulic cylinder, not

anenlarged upper end 22 extending above shown, by which the bottom 19and head 21 is supported in position to close the ingot mold 1, and bywhich the ingot when roperly cooled may be withdrawn throug i the lowerend of the mold by the engagement of,

the end of the ingot with the enlarged end 22 of the head 21, as shownin Fi 3. Attached to the under side of the lower head 13 is a cup shapedshell. 24 from which is suspended a tubular extension 25, with its upperend projecting into the shell 24 to form an annular space 26 which isconnected by a pipe .27 with a source of steam supply under pressure.The interior diameter of the ipe 25 is slightly larger than the interioriameter oi the ingot mold 1, so that when an ingot 23 is drawn throughthe .pipe 25, an annular space 29 will be formed around the ingot incommunication with the interior of the cup shapedshell 24, so that steamentering the annular space 26 in the shell 24 may pass over the upperend of the pipe 25 and downward into the annular space 2!) around theingot 28.

In order to secure a uniform distribution of steam around the ingot Iinterpose into the path of the steam an annular plate 30 having a seriesof small holes 31 through which the steam passes from the annular space26. Attached to the lower end of the pipe 25 is a tip 32 having thediameter of its lower or delivery end 33 contracted to the interiordiameter of the in ot mold 1, and around the interior of the deliveryend 33 are a series of longitudinal grooves 31 which, when the ingot 28fills the delivery end of. the tip, forms a series of channels throughwhich steam admitted through the upper end of the pipe 25 is allowed toescape.

The operation of my improved apparatus is as follows :The bottom 19carried by the end of the withdrawing rod 23 and having mounted thereona plastic wall or dam 20 made of some refractory material is inserted inthe lower end of the ingot mold 1, thereby closing the lower end of themold to the passage of molten metal. A current of coollng water is madeto pass through the annular chamber 11 surrounding the mold 1 and thelatter is filled with molten metal from the hopper 16 through therestricted opening 17 in the bottom of the ho per which is elevatedsomedistanoe above tlie open upper end of the ingot mold, in order thatthe metal may.

give off its neutral or other ases. The

- employment of water in the annular chamber 11 acting uponthe outsideof the thin pipe forming the ingot mold begins at once to cool the ingotand form a senu solidified shell 35 as indicated by the heavier shadingin Fig. 3. At the proper stage in the process of solidification alongitudinal movement is given to the withdrawing rod 23 either by ahydraulic cylinder, not shown, or by other suitable means, therebydrawing theingot from the lower end of the ingot mold 1 into and ingot.

through the extension tube 25, while at the same time a fresh sup )ly ofmolten metal is fed to the upper end oi the ingot. mold to [ill thespace'caused by the withdrawal of the The longitudinal movement of theingot and the supply of molten metal to the ingot mold are made tocorrespond with each other and both are regulated to correspond with thecooling of the metal in the mold. \Vhen the movement of the ingot andthe feeding of the fresh metal has thus been adjusted, the continuousl'ormation of an ingot in the mold will become automatic and as theupper end of the semi solidified shell 35 is drawn downward in the ingotmold, a clearance is ellected between the ingot and the inner taperingwall 2 of the ingot mold. As the ingot. passes the interior taperingwall 3 it is expanded to completely fill the mold by the weight of thesuperimposed column of molten metal. Am )le clearance is provided forthe ingot at the owcrend of the mold] by slightly Haring the lower endof the mold as shown at. 3, the enlargement of the inner diameter ol'the mold at its lower end being sutlicient to compensate for thedecreased expansion liable to exist at the extreme lower end of the moldowing to its being confined within the lower head 13 and subjected tothe initial cooling action of the stream of water passing through theannular space 11.- As the ingot is drawn through the extension tube 25it is further subjected to the cooling action of a current of steamunder pressure which is admitted through the pipe .27 to the annularspace 26, and passing through the. perforations 31 of the annular plate30 it enters the upper end of the pipe 25 and is crowded downward untilit escapes through the series of grooves 34 at the lower end of the tip32. As the grooves 34 form a restricted exit for steam from theextension pipe 25, a body of steam is maintained within the annularspace 29 having a pressure substantially equal to the initial pressureof the steam received through the pi e 25, said pressure being uniformlyapplied to the entire outer surface of the ingot and serving to resistthe lateral pressure of the vertical column 36 of fluid metal whichwould otherwise tend to bulge or expand the more or less plasticretainin wall of the ingot.

The length 0 the interior tapered wall 2 of the ingot mold relatively tothe entire length of the mold itself can only be determined by exeriment and it. will depend upon the rapi ity of the cooling process bywhich a semi-solidified shell or skin is formed u )on the ingot, andalso upon the longitudinal movement of the ingot as it is Withdrawn fromthe mold by the'withdrawing rod 23, but it should be of such length aswill afford a clearance to the ingot as it is withdrawn and allow theweight of the superimposed column of molten metal to-expand the shell tot e lower end of the ingotmold Where the ingot has already becomepartially cooled,

"and as the current of water rises in the annular space 11 toward thetop of the ingot mold, it will have already become heated as it flowsaround the more heated portion of the ingot mold.

As the ingot is withdrawn from the lower end of the ingot mold 1 itsouter shell or skin will have become thickened, while its interior orcore still remains in a fluid or semiflu1d state. In this condition theingot is drawn through the extension tube 25 sur-" rounded by a body,preferably of steam under pressure, which provides a yielding wall'incontact with the outer surface of the ingot and exerting a pressurethereon sufficient to withstand the interior pressure caused by thecolumn of molten metal forming the core of the ingot. As the steam isadmitted through the pipe 27 to the upper end of the extension tube 25it will become gradually superheated as it passes downward through theannular space 29 until it finds an exit at the lower end of theextension tube 25 through the grooves or channels 34. The greatestcooling efiect of the steam therefore is produced at the u per end ofthe extension tube 25 where tide ingot is the hottest, and as the ingotbecomes gradually cooler toward the lower end of the'extension tube 25,the steam becomes gradually hotter, so that its cooling effect upon theingot is greatly reduced. At the same time a radiant heat from the coreof the ingot is allowed'to diffuse itself through the already thickenedshell of the ingot,.so that the heat as the ingot leaves the extensiontube 25 has become uniformly diffused through the entire mass of theingot, this operation being substan tially the same as that nowpracticedin the I ordinary method of working ingots and known v thequality of t emetal somewhat similar to' as soaking.

The presence of ya yielding body like steam in the annular s ace29entirely surrounding the ingot enablbs the ingot to be drawn through theextension tube practically without friction. The sudden cooling of thein got at the upper end of the extension tube 25 by the first impact ofsteam and'the subsequent re-heating of the outer shell of the ingot hasa tem ering eflect which imprpves the well known effect roduced uponmetal by rapid cooling and eating and for this reason I have termed theextension tube with its annular sace 29 a tempering chamber, the suitale length of which can only be determined by experiment and dependingupon the size of the ingot, the temperature and pressure of the steam,the rapidity of movement of the ingot throughthe tern ering chamber andthe extent to which the ingot has been cooled when it leaves the in otmold.

' have shown in the accompanying drawings a'tempering chamber of nearlythe same length as the ingot mold, but it may be found advisable to makethe tempering chamber several times the length of the ingot mold, and Ithink it may profitably be made to extend from the in ct mold to therolls of a rolli mill by whic the ingot may be reduced in cross section.If such reducing rolls are placed near the delivery end of the tem eringchamber, the ingot will be practicafly protected from contact with theoutside air from the time it leaves the in ot mold until it enters thereducin rolls, an if under pressure or with neutral gases, the

I amount of oxidation of the ingot may be appreciably reduced.

It will beobserved, therefore, that the tempering chamber performs avariety of useful functions among which may be mentioned, first, thereduction of frictionupon the moving ingot; second,,the application ofpressure to resist the expansive power exerted by the fluid core of theingot; third, to

continue the operation of cooling and solidi-, fying the shel of theingot asit enters the tempering chamber; fourth, to produce a tempermgeffect upon the shell bf the ingot by which the quality of the metal isimproved; fifth, to secure a uniform diffusion of heat through the massof the ingot as it leaves the tempering chamber by the process ofsoaking, and sixth, to protect the ingot from undue oxidation.

What I claim as my invention and desire to secure by Letters Patentis 1. In an apparatus for casting ingots, the combination of an ingotmold having its uper or receiving end reduced in diameter to formslightly inclined sides, means for cooling the outer surface of theingot in the mold, and means for imparting a longitudinal movement .tothe ingot from the receiving end to- Ward the delivery end of the mold.

' 2. In an apparatus for casting ingots, the combination with an ingotmold openat both ends and having its up er or receiving end reduced indiameter to orm slightly inclined sides, means for cooling the outersurface of the ingot in the mold, means for feeding molten metal to thereceiving end of the mold, and means for withdrawing the ingot from thedelivery end of themold.

3. In an apparatus for casting ingots, the combination of an ingot moldhaving its de livery end increased in diameter, a removablebottom ofless diameter than the de' livery end of the mold, and a dam mounted onsaid bottom and closing the annular space around the bottom, and; meansfor cooling the ingot in said mold.

4. In an apparatus for casting ingots, the

with their opposing ends separated, an annular cup shaped shellinclosing the space between the mold and the receiving end of thechamber, and means for admitting steam to said cup shaped shell.

6. In an apparatus for eastin ingots, the

I combination with an ingot mol and a tempering chamber in alinementtherewith, but with their opposing ends separated, an annular cup shapedshell inclosing the space between the mold and the receiving end of thetempering chamber, and having an inclosed space for steam under pressurecommunicating with the tempering chamber.

7. In an apparatus for casting ingots, the combination with an ingotmold, of a tempering chamber of greater diameter than the mold and inalinement with said mold but separated therefrom, a shell inclosing thespace between the mold and the receiving end of said tempering chamber,and having an annular space for steam under pressure communicating withthe interior of said tempering chamber, whereby a yielding annular wallof compressed steam is provided between the ingot and the wall of thetempering chamber.

8'. In an apparatus for casting ingots, the combination with an ingotmold, of a tempering chamber in alinement with said mold and having itsinner diameter greater than the diameter of the ingot, thereby forming.an annular chamber around the ingot, means for admitting an annularblast of steam to the top of said chamber around said ingot and arestricted opening surrounding the ingot at the bottom of said chamberfor the escape of steam from said chamber, whereby steam under pressureis constantly maintained in said chamber.

S). In an apparatus for casting ingots, the combination with an-ingotmold, of a tempering chamber in alinement therewith but of greaterdiameter, an annular shell around the receiving end of said temperingchamber and having an inelosed annular chamber communicating with theinterior of said tempering chamber, means for admitting steam underpressure to said annular chamber, and a restricted opening at the lowerend of said tempering chamber for removing steam therefrom.

10. In an apparatus for casting ingots, the combination with an ingotmold, of an extension tube at the delivery end of said mold having itsinterior diameter reater than the diameter of the ingot, a meta lie headuniting said tube and mold and inclosing an annular space communicatingwith the interior of the extension tube, an inlet pipe to said annularspace and an outlet at the opposite end of the extension tube, wherebysteam admitted at the upper end of the extension tube may becomesuperheated by its contact with the heated ingot, and means for movingan in ct from the mold through said extension tu e.

11. In an apparatus for casting ingots, the combination with an ingotmold, of a pipe inclosing a chamber of larger diameter than said ingotmold, said chamber forming an extension of said mold and communicatingtherewith, said pipe provided at its ingot receiving end with an openingfor the admission of steam, and at its ingot delivery end with anopening for the escape of steam, with the area of said openings arrangedto allow the escape of steam more slowly than its entrance, whereby apredetermined pressure of steam may be maintained in said pipe incontact with said ingot.

' JOHAN O. E. TROTZ. -VVitnesses:

RUEUs B. FOWLER,

PENELOPE OOMBERBACHI

